The point of a vaccine trial is to test whether the vaccine works. If you get an answer to that question, the trial is a success. The answer may be “No”, in which case the vaccine is a failure, but the trial would still be a success. (The STEP HIV vaccine trial was therefore a success, though the vaccine was a failure.)

Malaria vaccines have been desperately needed forever, and in the past year there have been a few clinical trials. 1 An encouraging, though unspectacular, trial was reported last year, where the vaccine offered modest protection in children. 2

The most successful vaccines seem to be T-cell based, rather than antibody-based, and the latest report, of a Phase II trial in Kenya,3 drives another nail in the antibody/malaria coffin:

The FMP1/AS02 vaccine did not protect children living in Kombewa against first episodes of P. falciparum malaria; it did not reduce the overall incidences of clinical malaria episodes or of malaria infections, and did not reduce parasite densities … Because of the clearly demonstrated overall lack of efficacy in this trial, FMP1/AS02 is no longer a promising candidate for further development as a monovalent malaria vaccine. … We therefore propose that future MSP-142 vaccine development efforts should focus on other antigen constructs and formulations. 3

I don’t actually know much about the history of malaria vaccines, as far as trials go, so I don’t know how unusual it is to have clinical trials. People have been working on malaria vaccines for decades, but none have worked very well.[↩]